/**
 * Copyright 2018 The Feign Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */
package reactivefeign.utils;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;

public class MultiValueMapUtils {

  public static <K, V> void addAllOrdered(Map<K, List<V>> multiMap, K key, List<V> values) {
    multiMap.compute(key, (key_, values_) -> {
      List<V> valuesMerged = values_ != null ? values_ : new ArrayList<>(values.size());
      valuesMerged.addAll(values);
      return valuesMerged;
    });
  }

  public static <K, V> void addOrdered(Map<K, List<V>> multiMap, K key, V value) {
    multiMap.compute(key, (key_, values_) -> {
      List<V> valuesMerged = values_ != null ? values_ : new ArrayList<>(1);
      valuesMerged.add(value);
      return valuesMerged;
    });
  }

  public static <K, V> void addAll(Map<K, Collection<V>> multiMap, K key, Collection<V> values) {
    multiMap.compute(key, (key_, values_) -> {
      Collection<V> valuesMerged = values_ != null ? values_ : new ArrayList<>(values.size());
      valuesMerged.addAll(values);
      return valuesMerged;
    });
  }

  public static <K, V> void add(Map<K, Collection<V>> multiMap, K key, V value) {
    multiMap.compute(key, (key_, values_) -> {
      Collection<V> valuesMerged = values_ != null ? values_ : new ArrayList<>(1);
      valuesMerged.add(value);
      return valuesMerged;
    });
  }
}
